The automotive industry has turned to the use of interior trim components such as door panels comprising a polyvinyl chloride shell. See, for example, the trim components disclosed in U.S. Pat. No. 3,123,403. The acceptance of such components has been because inter alia this type of construction permits a wide latitude in styling and color, and grain effects which are most desired particularly in the interior design of automobiles.
The current state of the art includes a pre-formed grained vinyl shell made from dry thermoplastic plastisol particles which are applied to a heated shell mold from a supply box to form a continuous monochromatic one-piece shell.
In order to enhance the interior decor of an automobile, interior door panels and other parts have been proposed which include two separate plastic shell sections formed from different colored plastic joined by a separate connector strip at a connection joint.
The use of multi-color plastic is also known in the manufacture of colored filaments. Such manufacture includes use of a compartmented spinning head for making two-colored yarn as disclosed in U.S. Pat. No. 3,049,397 issued Aug. 14, 1962 for Process of Making Space-Dyed Yarn.
Apparatus and method for multiple colored thermoplastic floor materials are set forth in U.S. Pat. No. 3,383,442 issued May 14, 1968.
Also, the use of movable dividers in molds for molding products is known as practiced in U.S. Pat. No. 1,521,316, issued Dec. 30, 1924; U.S. Pat. No. 3,859,016, issued Jan. 7, 1975 and U.S. Pat. No. 4,335,068, issued June 15, 1982.
None of the aforesaid methods and apparatus for manufacture of plastic products is directed to a process or apparatus for manufacturing a single piece shell product, for example, an interior panel component of an automobile.